Mongodb计算多边形的面积

Question

嗨，我的mongodb上有这样的对象

{
  "_id" : ObjectId("53a9cf13a004869fb0476859"),
  "id" : NumberLong(4090259),
  "version" : "3",
  "changeset" : "10265399",
  "uid" : "136321",
  "user" : "Teddy73",
  "timestamp" : "2012-01-01T21:32:37Z",
  "poly" : {
    "type" : "Polygon",
    "coordinates" : [[
        [8.6030412, 49.6544071], [8.602331, 49.6556077],
        [8.6073617, 49.6575444], [8.6081741, 49.6564124], [8.6030412, 49.6544071]
    ]]
  },
  "natural" : "water",
  "source" : "landsat"
}

是否可以计算poly？

的面积

在Postgres中有一个名为

的函数

area()